Device and process for the contemporary capture of standard images and plenoptic images via correlation plenoptic imaging

Abstract

A process and device for the plenoptic capture of photographic or cinematographic images are described, both based on the correlation measure or “Correlation Plenoptic Imaging” (CPI), comprising the steps of splitting a primary light beam (6) coming from at least one light source in at least two distinct light beams (7, 8), directing said distinct light beams towards two image capturing sensors to capture images, so that the first light beam is directed towards at least one first capturing sensor to capture a spatial measure of a scene and the second light beam is directed towards a second capturing sensor to capture an angular measure of said scene, said angular measure being adapted to provide the propagation direction of the light beam coming from the scene, said spatial measure being adapted to provide the conventional two-dimensional capture of the image of the scene. The device further comprises a main focal lens (Lb) arranged along the optical path of the first light beam, said main focal lens (Lb) and second sensor (14) being arranged so that the length of the light's optical path between the light source (4) and the second sensor (14) is substantially equal to the length of the light's optical path between the light source (4) and said main focal lens (Lb).

The invention claimed is: 
     
       1. A process for the plenoptic capture of photographic, cinematographic, microscopic or stereoscopic images of a scene, comprising the steps of:
 splitting a primary light beam ( 6 ) coming from at least one light source ( 4 ) in a first light beam ( 7 ) and a second light beam ( 8 ) by means of a splitting element ( 11 ), wherein said at least one light source ( 4 ) is selected from a source of chaotic light or a source of entangled photons; 
 directing said first light beam ( 7 ) and said second light beam ( 8 ) respectively towards first sensor means ( 13 ) to capture a spatial measure of said scene and towards second sensor means ( 14 ) to capture an angular measure of said scene, said first light beam ( 7 ) being adapted to be either reflected by said scene or transmitted through said scene, said angular measure being adapted to provide the propagation direction of said first light beam ( 7 ) reflected by said scene or transmitted through said scene, said spatial measure being adapted to provide the image of said scene, 
 wherein said first light beam ( 7 ) is passed through a main focal lens (Lb) arranged along the light's optical path between said scene and said first sensor means ( 13 ), 
 wherein said second light beam ( 8 ) is passed through a second focal lens (La) arranged along the light's optical path between said splitting element ( 11 ) and said second sensor means ( 14 ), wherein said second focal lens (La) is arranged so as to meet the following equation:
   1 /za+ 1/ zb= 1 /F    
 
 where za is the length of the light's optical path between said second focal lens (La) and said light source ( 4 ), zb is the length of the light's optical path between said second focal lens (La) and said second sensor means ( 14 ), and F is the focal length of said second focal lens (La), and wherein said second focal lens (La) is designed so as to reproduce, on said second sensor means ( 14 ), the first-order image of the light source ( 4 ), and 
 wherein said first sensor means ( 13 ) captures the spatial measure, and captures the first-order image of an object ( 5 ) of the scene. 
 
     
     
       2. The process according to  claim 1 , further comprising the step of processing said spatial measure and said angular measure both captured by said first and second sensor means ( 13 ,  14 ) through a process of correlating said spatial measure and said angular measure for obtaining a plenoptic image. 
     
     
       3. The process according to  claim 2 , wherein said process of correlating said spatial measure and said angular measure comprises correlating each pixel of said first sensor means ( 13 ) with at least one pixel of said second sensor means ( 14 ). 
     
     
       4. The process according to  claim 1 , wherein said first sensor means ( 13 ) and said second sensor means ( 14 ) are selected from two distinct image capturing sensors to capture images or two distinct portions of an image capturing sensor to capture images. 
     
     
       5. The process according to  claim 1 , wherein said second light beam ( 8 ) is directed onto said second sensor means ( 14 ) by means of at least one reflective element ( 12 ), and in that said first light beam ( 7 ) is directed onto said first sensor means ( 13 ) by means of at least one reflective element ( 12 ). 
     
     
       6. The process according to  claim 1 , wherein said second light beam ( 8 ) is passed through an additional focal lens (L) arranged along the light's optical path between said splitting element ( 11 ) and said second sensor means ( 14 ) so as to meet the following equation:
   1/ S+ 1/ S′= 1/ F    
 wherein S is substantially equal to the length of the optical path between said at least one light source ( 4 ) and said main focal lens (Lb), added to the length of the optical path between said at least one light source ( 4 ) and said additional focal lens (L), 
 S′ is substantially the length of the optical path between said additional focal lens (L) and said second sensor means ( 14 ), and F is the focal length of said additional focal lens (L). 
 
     
     
       7. The process according to  claim 1 , wherein said first light beam ( 7 ) is passed through an additional focal lens (L) arranged along the light's optical path between said splitting element ( 11 ) and said main focal lens (Lb) so as to meet the following equation:
   1/ S+ 1/ S′= 1/ F    
 wherein S is substantially equal to the length of the optical path between said main focal lens (Lb) and said additional focal lens (L), S′ is substantially equal to the length of the optical path between said at least one light source ( 4 ) and said additional focal lens (L), added to the length of the optical path between said at least one light source ( 4 ) and said second sensor means ( 14 ), 
 and F is the focal length of said additional focal lens (L). 
 
     
     
       8. The process according to  claim 1 , wherein said light source ( 4 ) is a source of chaotic light, the statistics and development over time of the chaotic source being known, said source of chaotic light being made by means of a coherent-light source adapted to emit a coherent-light beam and by means of a programmable device producing variations that are known but each time different in the phase and amplitude of the beam of coherent light, comprising the steps of:
 emitting said first light beam ( 7 ) of chaotic light having known statistics by means of said light source ( 4 ), 
 directing said first light beam ( 7 ) towards said first sensor means ( 13 ) to capture a spatial measure of said scene, said first light beam being adapted to be either reflected by said scene or transmitted through said scene, said spatial measure being adapted to provide the image of said scene, 
 calculating the propagation direction of said second light beam ( 8 ) directed towards a virtual plane properly selected to capture an angular measure of said scene, said angular measure being adapted to provide the propagation direction of said first light beam reflected by said scene or transmitted through said scene, wherein said second light beam ( 8 ) is a virtual light beam, the correlation between the intensity, or the intensity fluctuation, and the intensity expected for said virtual light beam adapted to calculate the angular measure being provided by a software, and the light intensity over time that would be measured by second sensor means ( 14 ) for the angular measure, if these were placed on said virtual plane, can be calculated, 
 wherein said first light beam ( 7 ) is passed through a main focal lens (Lb) arranged along the light's optical path between said scene and said first sensor means ( 13 ), wherein said main focal lens (Lb) is arranged so that the length of the light's optical path between said at least one light source ( 4 ) and said main focal lens (Lb) is substantially equal to the length of the light's optical path between said at least one light source ( 4 ) and said virtual plane. 
 
     
     
       9. The process according to  claim 8 , wherein said light source ( 4 ) comprises a source of coherent light and a spatial light modulator (SLM). 
     
     
       10. A device for the plenoptic capture of photographic, cinematographic, microscopic or stereoscopic images of a scene, comprising:
 first sensor means ( 13 ) and second sensor means ( 14 ) to capture images, 
 at least one splitting element ( 11 ) adapted to split a primary light beam ( 6 ) coming from at least one light source ( 4 ) in a first light beam ( 7 ) directed towards said first sensor means ( 13 ) and a second light beam ( 8 ) directed towards said second sensor means ( 14 ), said first light beam ( 7 ) being adapted to be reflected by said scene or transmitted through said scene, wherein said at least one light source ( 4 ) is selected from a source of chaotic light or a source of entangled photons; 
 said first sensor means ( 13 ) being designed to capture a spatial measure adapted to provide the image of said scene, said second sensor means ( 14 ) being designed to capture an angular measure adapted to provide the propagation direction of said first light beam ( 7 ) reflected by said scene or transmitted through said scene, 
 a main focal lens (Lb) arranged along the optical path of said first light beam ( 7 ) between said scene and said first sensor means ( 13 ), 
 a second focal lens (La) arranged along the optical path of said second light beam ( 8 ) between said splitting element ( 11 ) and said second sensor means ( 14 ), wherein said second focal lens (La) is arranged so as to meet the following equation:
   1 /za+ 1 /zb= 1/ F    
 
 where za is the length of the light's optical path between said second focal lens (La) and said light source ( 4 ), zb is the length of the light's optical path between said second focal lens (La) and said second sensor means ( 14 ), and F is the focal length of said second focal lens (La), and wherein said second focal lens (La) is designed so as to reproduce, on said second sensor means ( 14 ), the first-order image of the light source ( 4 ), and 
 wherein said first sensor means ( 13 ) captures the spatial measure, and captures the first-order image of an object ( 5 ) of the scene. 
 
     
     
       11. The device according to  claim 10 , wherein said first sensor means ( 13 ) and said second sensor means ( 14 ) are selected from two distinct image capturing sensors to capture images or two distinct portions of an image capturing sensor to capture images. 
     
     
       12. The device according to  claim 10 , further comprising at least one reflective element ( 12 ) adapted to direct said second light beam ( 8 ) towards said second sensor means ( 14 ), and/or at least one reflective element ( 12 ) adapted to direct said first light beam ( 7 ) towards said first sensor means ( 13 ). 
     
     
       13. The device according to  claim 10 , comprising an additional focal lens (L) arranged along the optical path of said second light beam ( 8 ) between said splitting element ( 11 ) and said second sensor means ( 14 ) so as to meet the following equation:
   1/ S+ 1/ S′= 1/ F    
 wherein S is substantially equal to the length of the optical path between said at least one light source ( 4 ) and said main focal lens (Lb), added to the length of the optical path between said at least one light source ( 4 ) and said additional focal lens (L), 
 S′ is substantially the length of the optical path between said additional focal lens (L) and said second sensor means ( 14 ), 
 and F is the focal length of said additional focal lens (L). 
 
     
     
       14. The device according to  claim 11 , comprising an additional focal lens (L) arranged along the optical path of said first light beam ( 7 ) between said splitting element ( 11 ) and said main focal lens (Lb) so as to meet the following equation:
   1/ S+ 1/ S′= 1/ F    
 wherein S is substantially equal to the length of the optical path between said main focal lens (Lb) and said additional focal lens (L), 
 wherein S′ is substantially equal to the length of the optical path between said at least one light source ( 4 ) and said additional focal lens (L), added to the length of the optical path between said at least one light source ( 4 ) and said second sensor means ( 14 ), 
 and F is the focal length of said additional focal lens (L). 
 
     
     
       15. The device according to  claim 10 , wherein said light source ( 4 ) is a source of chaotic light, the statistics and development over time of the chaotic source being known, said source of chaotic light being made by means of a coherent-light source adapted to emit a coherent-light beam and by means of a programmable device producing variations that are known but each time different in the phase and amplitude of the beam of coherent light, wherein said light source ( 4 ) is designed to emit a first beam ( 7 ) of chaotic light having known statistics, first sensor means ( 13 ) to capture a spatial measure of said scene, said first light beam ( 7 ) being adapted to be either reflected by said scene or transmitted through said scene, said spatial measure being adapted to provide the image of said scene, said device further comprising means to calculate the spatio-temporal propagation of a second light beam ( 8 ) directed towards a virtual plane to capture an angular measure of said scene, said angular measure being adapted to provide the propagation direction of said first light beam ( 7 ) either reflected by said scene or transmitted through said scene, wherein said second light beam ( 8 ) is a virtual light beam, the correlation between the intensity, or the intensity fluctuation, and the intensity expected for said virtual light beam adapted to calculate the angular measure being provided by a software, and the light intensity over time that would be measured by second sensor means ( 14 ) for the angular measure, if these were placed on said virtual plane, can be calculated. 
     
     
       16. The device according to  claim 15 , wherein said light source comprises a source of coherent light and a spatial light modulator (SLM).